The present invention relates to communication circuits that include a microphone and a loudspeaker, and, more particularly, to microphone circuits and methods for reducing loudspeaker feedback and echo.
When a communication system includes a microphone and loudspeaker that are closely spaced, some sound from the loudspeaker may be sensed by the microphone and fed back through the communication system. Such feedback can create an echo effect where, for example, a user's voice is fed back to the user and heard as an echo.
Echo cancellation circuits have been employed in communication systems, for example, in land-line phones, to reduce the feedback from a loudspeaker through a microphone. However, in noisy environments and/or where long time delays may occur in the feedback of sound, some echo cancellation circuits can negatively affect the quality of the sound that is provided by the microphone and can, for example, increase echoes or introduce unwanted noise.